Movement Through the Cell
Membrane
1. Review: What are the building blocks of
lipids?
2. Sketch a lipid molecule in the space
below. Label your sketch!
1. Review: What are the building blocks of
lipids? Glycerol and fatty acids
2. Sketch a lipid molecule in the space
below. Label your sketch!
1. Review: What are the building blocks of
lipids? Glycerol and fatty acids
2. Sketch a lipid molecule in the space
below. Label your sketch!
Fatty Acids
Glycerol
3. What is the function of the cell membrane?
4. Describe the structure of a lipid bilayer.
5. In addition to lipids, list 2 other types of
molecules found in the cell membrane.
a. _____________
b. _______________
3. What is the function of the cell membrane?
Regulate what enters and leaves the cell; protect
and support the cell
4. Describe the structure of a lipid bilayer.
5. In addition to lipids, list 2 other types of
molecules found in the cell membrane.
a. _____________
b. _______________
3. What is the function of the cell membrane?
Regulate what enters and leaves the cell; protect
and support the cell
4. Describe the structure of a lipid bilayer.
Double-layered sheet of lipid molecules;
hydrophilic heads point out, hydrophobic tails
point in
5. In addition to lipids, list 2 other types of
molecules found in the cell membrane.
a. _____________
b. _______________
3. What is the function of the cell membrane?
Regulate what enters and leaves the cell; protect
and support the cell
4. Describe the structure of a lipid bilayer.
Double-layered sheet of lipid molecules;
hydrophilic heads point out, hydrophobic tails
point in
5. In addition to lipids, list 2 other types of
molecules found in the cell membrane.
a. proteins
b. _______________
3. What is the function of the cell membrane?
Regulate what enters and leaves the cell; protect
and support the cell
4. Describe the structure of a lipid bilayer.
Double-layered sheet of lipid molecules;
hydrophilic heads point out, hydrophobic tails
point in
5. In addition to lipids, list 2 other types of
molecules found in the cell membrane.
a. proteins
b. carbohydrates
http://www.sciencefriday.com/videos/watch/10210
6. Label the diagram of a cell membrane shown
below:
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
Lipid bilayer
7. Define the following terms:
a. solution:
b. solute:
c. solvent:
d. concentration:
7. Define the following terms:
a. solution: mixture of 2 or more substances
in which molecules are evenly distributed
b. solute:
c. solvent:
d. concentration:
7. Define the following terms:
a. solution: mixture of 2 or more substances
in which molecules are evenly distributed
b. solute: substance that is dissolved in a
solution
c. solvent:
d. concentration:
7. Define the following terms:
a. solution: mixture of 2 or more substances
in which molecules are evenly distributed
b. solute: substance that is dissolved in a
solution
c. solvent: substance in which the solute is
dissolved
d. concentration:
7. Define the following terms:
a. solution: mixture of 2 or more substances
in which molecules are evenly distributed
b. solute: substance that is dissolved in a
solution
c. solvent: substance in which the solute is
dissolved
d. concentration: mass of solute in a given
volume of solution
8. During the process of diffusion, molecules tend
to move from
to
until the solution
reaches equilibrium.
9. Does diffusion require energy? _______ Explain.
8. During the process of diffusion, molecules tend
to move from an area of high concentration to
until the solution
reaches equilibrium.
9. Does diffusion require energy? _______ Explain.
8. During the process of diffusion, molecules tend
to move from an area of high concentration to
an area of low concentration
until the solution
reaches equilibrium.
9. Does diffusion require energy? _______ Explain.
8. During the process of diffusion, molecules tend
to move from an area of high concentration to
an area of low concentration
until the solution
reaches equilibrium.
9. Does diffusion require energy? __NO__ Explain.
Molecules naturally move from HIGH concentration
to LOW concentration
Example of Diffusion:
• The smell of popcorn
after it’s been popped.
• Does the smell of
popcorn stay where the
popcorn was popped?
Why or why not?
10. Why are biological membranes described as
selectively permeable?
11. What is osmosis?
10. Why are biological membranes described as
selectively permeable? Some substances can
pass through the membrane while other substances
cannot
11. What is osmosis?
10. Why are biological membranes described as
selectively permeable? Some substances can
pass through the membrane while other substances
cannot
11. What is osmosis? Diffusion of water across a
membrane
12. Label the drawing below to show how osmosis
works.
water
Cell
Membrane
glucose
Figure 7-15 Osmosis
Figure 7-15 Osmosis
13. Define the following terms:
a. hypertonic:
b. hypotonic:
c. isotonic:
14. Cells are almost always __________ to fresh water,
meaning there will be a net movement of water ____ the cell.
Describe two ways that cells keep from bursting in fresh
water environments:
a.
b.
13. Define the following
terms:
a. hypertonic: Solution
has a higher solute
concentration than the
cell
• Water leaves the cell,
animal cells can shrink.
b. hypotonic: lower
concentration of solute
• Water enters the cell, animal cells can
expand and possibly burst.
• Plant and bacteria cells have their cell
walls that provides provide protection
from too much osmotic pressure
Isotonic
• The concentration of
the solutes is the
same inside and
outside the cell.
• Water goes in and out
at the same rate and
pressure doesn’t
change
14. Cells are almost always __________
to fresh water, meaning there will be a
net movement of water ____ the cell.
Describe two ways that cells keep from
bursting in fresh water environments:
a.
b.
14. Cells are almost always hypertonic
to fresh water, meaning there will be a
net movement of water ____ the cell.
Describe two ways that cells keep from
bursting in fresh water environments:
a.
b.
14. Cells are almost always hypertonic
to fresh water, meaning there will be a
net movement of water into the cell.
Describe two ways that cells keep from
bursting in fresh water environments:
a.
b.
14. Cells are almost always hypertonic
to fresh water, meaning there will be a
net movement of water into the cell.
Describe two ways that cells keep from
bursting in fresh water environments:
a. cell walls keep cell from expanding
b.
14. Cells are almost always hypertonic
to fresh water, meaning there will be a
net movement of water into the cell.
Describe two ways that cells keep from
bursting in fresh water environments:
a. cell walls keep cell from expanding
b. contractile vacuole pumps extra
water out of cell
http://www.youtube.com/watch?v=OYoaLzobQmk
15. What is facilitated diffusion?
16. Label the diagram to show how facilitated diffusion
works:
15. What is facilitated diffusion? Diffusion of molecules
across a cell membrane through a special protein channel
16. Label the diagram to show how facilitated diffusion
works:
Protein channel
Glucose
molecules
High
concentration of
solute
Low
concentration of
solute
Cell Membrane
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_facilita
17. What is active transport?
18. Label the diagram to show how active transport works:
17. What is active transport? Molecules pumped through
special protein channels from low concentration to high
concentration
18. Label the diagram to show how active transport works:
Cell Membrane
Energy
Cell Membrane
Protein
channel
Molecule
to be
carried
Protein
channel
Low
High
concentration
concentration
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_the_s
19. Define the following terms:
a. endocytosis:
b. phagocytosis:
c. exocytosis:
19. Define the following terms:
a. endocytosis: process of cellular ingestion by which
the cell membrane folds inward to bring substances into the
cell.
b. phagocytosis:
c. exocytosis:
19. Define the following terms:
a. endocytosis: process of cellular ingestion by which
the cell membrane folds inward to bring substances into the
cell.
b. phagocytosis: (another name for endocytosis)
c. exocytosis:
19. Define the following terms:
a. endocytosis: process of cellular ingestion by which
the cell membrane folds inward to bring substances into the
cell.
b. phagocytosis: (another name for endocytosis)
c. exocytosis: removal of material from a cell; membrane
surrounding material fuses with cell membrane to force
material out
20. Complete the following chart to compare types of
movement through a cell membrane:
Types of molecules
transported
Diffusion
Small molecules
Special channel
required?
Energy reguired?
no
no
Osmosis
water
no
no
Facilitated
diffusion
ions, sugars
(glucose), salts
yes
no
ions (H+, K+,
Na+, Ca2+)
yes
Active transport
yes